The present invention generally relates to turf removal equipment, and it is specifically directed to a self-powered machine capable of lifting and removing artificial athletic turf from the base surface upon which it lies, granulating and segregating the turf's infill particles component from its tufted and coated substrate sheet component, particlizing the tufted and coated substrate component, and depositing collected infill material particles and substrate material particles into separate storage units so that the respective material mixtures may be transported off-site to undergo any further processing needed to prepare them for reuse as infill material in a future turf installation.
Artificial athletic turf is generally comprised of at least one sheet layer of fabric backing substrate through which filament yarn is inserted, via a tufting process, to form a grass-resembling pile that is further bonded to the backing by application of coating material onto the bottom face of the backing and yarn backloops. For installation as a playing surface, the turf is laid atop a resilient base mat that helps to help cushion athletes' joints and give the turf surface a more natural feel. Thereafter, a granular mix of small particles (typically, rubber and sand particles), called “infill,” is poured atop the tufted backing to occupy space between the synthetic grass blades much like natural soil would. So, in addition to improving playing surface resiliency, this infill material imposes a protective barrier between the athletes' cleats and the backing fabric.
Artificial turf has long been used as a playing surface for sports that are traditionally played on grass fields, such as football, baseball, and soccer. In fact, in parts of the United States that experience exceedingly precipitous weather, an artificial playing surface may be viewed as almost essential to playing those sports outdoors during certain times of year. For example, in the Great Lakes geographic region, artificial turf may be preferred over natural grass as an American football outdoor playing surface because of the likelihood that a natural surface will harden and become more difficult to maintain during prolonged cold weather typically experienced throughout the traditional autumn football season. At the same time, in the Pacific Northwest region, a water permeable synthetic surface may be preferable because of the water puddle formation and overall deterioration that a natural surface would experience due to region's excessive rainfall. Conversely, because the arid conditions of the desert Southwest region require that a natural grass field be extensively irrigated, synthetic turf is often preferred as an outdoor sports playing surface there as well. Furthermore, an artificial turf surface permits sports traditionally performed on natural grass to be played in climate-controlled indoor facilities, as artificial turf does not require the sunlight exposure needed to sustain natural grass. Nevertheless, a heavily used sports turf field, in any climate, will eventually experience enough wear and to necessitate replacement of its tufted and coated substrate component, if not its infill component before that.
Historically, the proposition of de-installing an artificial turf field has involved winding up, into large rolls, sections of tufted backing sheet, loading those rolls onto a hauling vehicle, and transporting them to a disposal site (e.g., a landfill). However, by conventional methods, the proposition of removing an entire sports field of artificial turf can be a quite laborious and time consuming, and it requires use of several men and/or units of machinery of different functions. Moreover, operators of many landfill sites will not even permit dumping of these large because of the highly inefficient use of space that doing so represents.
Consider that a typical American football field, for example, may comprise an artificial turf surface spanning 57,600 ft.sup.2 and weighing, with infill, approximately 1,060,000 total lbs. (18.4 lbs./ft.sup.2). Consider, further, that such a turf field is typically formed by an aggregation of 160 ft. by 15 ft. sections (24 sections in total) that adjacently lie atop the base surface. It generally takes a crew of at least three men to crimp a 15 ft. wide end of a section and initiate the winding up of any portion of its 160 ft. length. Then, after a roll is begun to be formed, a bulldozer or other power machine must be employed to continue pushing and winding up the section until, because of increasing weight of the enlarging roll, the section must be severed and the roll completed. Typically, a 160 ft. long section of turf is cut at approximately 30-foot intervals so that it is wound into 5 separate rolls, weighing almost 8,300 lbs. each, that can be fork lifted onto a flatbed truck and hauled off-site for further processing or disposal. Thus, up to 120 repetitions of this winding and lifting process need be performed, with all of the time and manpower implied thereby.
It should also be noted that, conventional artificial turf removal methods can be quite wasteful in that they may involve the discarding of sand and rubber infill material that could have been reused in a future turf installation. Furthermore, testing has shown that the mix of polymers that often comprise the tufted and coated substrate, such as polyethylene, polypropolene and urethane, can by recycled by extrusion and, when augmented with additives like natural rubber, may exhibit sufficient durometer to, itself, be later used as infill material in an athletic turf installation. Thus, when an infill-laden turf is simply buried or otherwise abandoned, potentially hundreds of thousands of dollars worth of infill material for use on future sports turf is, in effect, lost with it.
Therefore, at some juncture within the artificial turf removal process, it is desirable to salvage infill material by extracting it from the turf's substrate sheet. One rudimentary way to accomplish this is by using a human or vehicle-draw raking implement to loosen any compacted infill particles and then using suction or blow means to collect those particles. Of course, however, while this may salvage infill that retains commercial value, it likely involves a considerable amount of man work, powered machine operation, and, presumably, cost even before any effort or cost is expended winding up or otherwise displacing the turf. Consequently, apparatuses that can more sophisticatedly extract infill from turf substrates have been devised in the prior art. For examples, U.S. Pat. Nos. 5,562,779 to Allaway, et al. and 5,902,414 to Keal, et al. disclose embodiments of vehicle-drawn apparatuses capable of jet spraying compressed air at an incline angle against artificial turf in order to dislodge infill particles from the substrate and direct them into a collection chamber. The collected infill material can then be cleaned and re-deposited onto the substrate, or it can be retained for use with an altogether different turf. However, despite the obvious benefit of salvaging infill material, employing these, and similar, machines of the prior art may simply lengthen the de-installation process by virtue of adding an infill extraction step to be performed on the tufted substrate sheet prior to the step of removing it from the base surface. Furthermore, known machines do not obviate the aforementioned need to utilize the efforts of several workers and/or multiple units of equipment just to carry out the work of removing the substrate. In fact, that the present inventor is aware of, there is no single prior art apparatus capable of performing both an infill extraction function and a substrate sheet removal function near simultaneously.
Therefore, one can appreciate an outstanding need for an individual, self-contained apparatus capable of: (1) displacing continuous strips of artificial athletic turf from a base surface, (2) dislodging the displaced turf's infill material component from its tufted and coated backing component, (3) separately collecting each set of the segregated materials, and (4) appropriately preparing them for disposal or, more likely, storage and potential deployment in a future synthetic turf installation. The turf collecting apparatus of the present invention substantially fulfills this need.